/*
 * Integrated Rule Inference System (IRIS):
 * An extensible rule inference system for datalog with extensions.
 * 
 * Copyright (C) 2008 Semantic Technology Institute (STI) Innsbruck, 
 * University of Innsbruck, Technikerstrasse 21a, 6020 Innsbruck, Austria.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
 * MA  02110-1301, USA.
 */
package org.deri.iris.terms.concrete;

import java.math.BigDecimal;
import java.net.URI;

import org.deri.iris.api.terms.concrete.IDoubleTerm;

/**
 * <p>
 * Simple implementation of the IDoubleTerm.
 * </p>
 */
public class DoubleTerm extends AbstractNumericTerm implements IDoubleTerm {

	private final Double value;

	private BigDecimal decimalValue;

	DoubleTerm(float value) {
		this(Double.valueOf(Float.toString(value)));
	}

	DoubleTerm(double value) {
		this.value = value;
	}

	public BigDecimal getValue() {
		if (isNotANumber() || isPositiveInfinity() || isNegativeInfinity()) {
			return null;
		}

		if (decimalValue == null) {
			decimalValue = new BigDecimal(Double.toString(value));
		}

		return decimalValue;
	}

	public boolean isNotANumber() {
		return value.equals(Double.NaN);
	}

	public boolean isPositiveInfinity() {
		return value.equals(Double.POSITIVE_INFINITY);
	}

	public boolean isNegativeInfinity() {
		return value.equals(Double.NEGATIVE_INFINITY);
	}

	@Override
	public int hashCode() {
		return value.hashCode();
	}

	public URI getDatatypeIRI() {
		return URI.create(IDoubleTerm.DATATYPE_URI);
	}

}
